North Korea's spectacular destruction of its liaison office with the South is part of a series of staged provocations aimed at forcing concessions from Seoul and Washington, analysts say.

The South's President Moon Jae-in initially brokered a dialogue between Pyongyang and Washington, but the North now blames him for not persuading the US to relax sanctions.

Inter-Korean relations have been in deep freeze for months, following the collapse of a summit in Hanoi between North Korean leader Kim Jong Un and US President Donald Trump. That meeting foundered on what the nuclear-armed North would be willing to give up in exchange for a loosening of sanctions.

North Korea yesterday said it had rejected a South Korean offer to send special envoys to ease escalating tension. On Monday, Moon offered to send his national security adviser Chung Eui-yong and spy chief Suh Hoon as special envoys, North's KCNA state news agency said.

But Kim Yo Jong, the sister of North Korean leader Kim Jong Un and a senior ruling party official, "flatly rejected the tactless and sinister proposal".

In a separate KCNA dispatch yesterday, a spokesman for the General Staff of the (North) Korean People's Army said it would dispatch troops to Mount Kumgang and Kaesong near the border, where the two Koreas had carried out joint economic projects in the past.

"Internally, North Korea is deeply disappointed in Moon and appears determined to end inter-Korean ties," said Kim Keun-sik, professor of political science at Kyungnam University.

"By doing so, it is sending a message in its brinkmanship tactics to Trump that he should resume talks or lift economic sanctions as it has demanded so long."

The North's actions appear to be carefully calibrated, with Pyongyang drawing out the process by issuing multiple incremental warnings from different official sources -- leadership, government departments and the military -- ahead of each step it takes.

The US could be next in North Korea's sights: Pyongyang has warned Washington to stay out of inter-Korean affairs if it wants to ensure a smooth presidential election in November. But such a move would be fraught with risk for Pyongyang.

"The North should realise its brinkmanship tactic will not work this time, neither with Washington nor Seoul", said Kyungnam's Kim. "If it needs a change in status quo so desperately, then it must change its calculations instead of expecting the US to do so."